A quick glance at our Facebook timelines and we could make a pretty good guess at the most popular tourist destinations of the 21st century. Machu Picchu, the Northern Lights and the pyramids would all likely feature. Machu Picchu in Peru.  However, Smithsonian Magazine has compiled their picks with an added twist. They have listed the top 20 attractions and sites that have defined the 21st century, whether they be of scientific, artistic or historical importance. The top 20 destinations according to the publication are as follows:

1. The world's largest cave, Hang Son Doong in Vietnam.

Picture of cavers inside Hang Son Doong cave in Vietnam. pic.twitter.com/a2oN2JsmuJ

— Kent Palmer (@kepamer) September 7, 2015

2. Cern Laboratory, Switzerland, home of the God Particle

 

3. Virgin Galactic's Spaceport America, New Mexico

 

4. The last 800 western lowland gorillas (DRC, Uganda and Rwanda)

 

Heart disease is the leading cause of death in male Western lowland gorillas in North Amer… http://t.co/KQp6RigYUG pic.twitter.com/nqLIOhlsZH — QT Animals (@qt_animals) May 21, 2015

5. The Alma telescope in Chile which captures the world's starriest night sky

The ALMA array telescope gazes up at the star-filled night sky in the Atacama Desert in Chile. #ESO #BeautifulSky pic.twitter.com/H6keKmjQFy

— eHardin ♱ (@eHardinda) November 29, 2014

6. The shrinking glaciers of the Mendenhall Ice Caves, Alaska

 

7. Ferrari World in Abu Dhabi, the world's fastest rollercoaster

 

Because no #FerrariWorld visit is complete without the world's fastest roller coaster: http://t.co/JX2Mc8AUk1 #autos pic.twitter.com/8c6Qspslqe — driving.ca (@drivingdotca) September 20, 2015

8. Cayman trench in the Caribbean Sea, the deepest dive in the world

9. The Museum of Islamic Art, Qatar, opened in 2008

This photograph captured a moment in time, a memory of a summer evening leaving the Museum of Islamic Art in #Qatar pic.twitter.com/WlgIKJmg8S

— M barak Cherguia (@CherguiaMbark) April 20, 2015

10. Copenhagen's Noma, the world's best restaurant

 

11. Havana, Cuba, the rapidly changing "trade sanction-preserved time capsule"

 

12. Leicester, recently discovered resting place of King Richard III

 

Went to see the tomb of King Richard III. What a beautiful cathedral Leicester has! pic.twitter.com/v93guP8RN5 — Leighton T. James (@mrleightonjames) April 22, 2015

13. The flower shrine of Haifa, Israel

14. Icestock music festival, Ross Island, Antarctica

Before @Metallica played the "1st" concert in #Antarctica, Icestock rocked McMurdo for 25 yrs. http://t.co/btOj0TtKPj pic.twitter.com/dGJzFmcGTn

— Peter Rejcek (@poliepete) January 8, 2014

15. The 'throbbing' temple of New Delhi, India, opened in 2005

 

16. John Muir Way, Falkirk

 

17. The Door to Hell in the Karakum Desert, Turkmenistan, a natural gas cavern discovered in 1971

 

The Door to Hell: Burning Gas Crater in the Karakum Desert http://t.co/DLKktNuQNR pic.twitter.com/DI6FKvbnAn — Emanuel Ungaro (@BimmerMonkey) May 27, 2014

18. The Gates of Heaven skywalk, Tianmen Mountain, Hunan Province, China

19. A hair-raising cross country trip on Ecuador's railways, taking in one of the most biodiverse environments on the planet

Dare to tackle the infamous 'Devil's Nose' on what is known as 'the most difficult railway in the world'? #Ecuador pic.twitter.com/UFkkUUKj3f

— PlanSouthAmerica (@PlanSAmerica) April 13, 2015

20. Ellis Island Hospital, New York, reopened in 2014

Hat tip: i100.